utf8 math characters from source code file with minted in XeLaTeX

Question

I want XeLaTeX/minted to display all my mathematical characters from my .java source file.

More detailed: I file my programming homework in PDF documents in my university. I have been using LaTeX and listings to import my source code. I do a lot of mathematical programming and use a lot of mathematical symbols in my comments. As listings doesn't support utf-8 characters I have slowly been switching to minted + XeLaTeX. I keep common mathematical characters in a text file on my computer and copy them over to my .java files when commenting.

Let's consider following .tex file which I compile with $ xelatex -shell-escape minimal.

\documentclass[a4paper,oneside]{article}
\usepackage{fontspec}
\usepackage{xunicode}
%\usepackage{unicode-math}

% default, bw, perldoc
\usepackage{minted}
\usemintedstyle{perldoc}

\begin{document}

Document symbols.

≠≤≥×·÷±∓√~≈≅⇔¬∧∨∀∃∅∈∉⊆⊂∪∩∆ℕℤℝℂ∞Σ∑∏∫π

\begin{minted}{java}
// Java code
// ≠≤≥×·÷±∓√~≈≅⇔¬∧∨∀∃∅∈∉⊆⊂∪∩∆ℕℤℝℂ∞Σ∑∏∫π
\end{minted}

\end{document}

It only displays the characters ×·÷±√~¬∞∑ (PDF). Why is that? And is there a solution?

Answer 1

The problem is that the font you're using, that is, Latin Modern, doesn't have the glyphs you want to be printed; you find in the log file something such as

Missing character: There is no ≠ in font [lmmono10-regular]!
Missing character: There is no ≤ in font [lmmono10-regular]!
Missing character: There is no ≥ in font [lmmono10-regular]!
Missing character: There is no ∓ in font [lmmono10-regular]!

The solution is to use a font that has these glyphs. The ~ has a special meaning in LaTeX, so either you input it as \string~ (not in the minted context) or set

\AtBeginDocument{\catcode`~=12 }

but this can break many constructs, so I don't recommend it.

\documentclass[a4paper,oneside]{article}
\usepackage{fontspec}
\setmainfont{FreeSerif}
\setmonofont{FreeMono}

% default, bw, perldoc
\usepackage{minted}
\usemintedstyle{perldoc}

\begin{document}

Document symbols.

≠≤≥×·÷±∓√\string~≈≅⇔¬∧∨∀∃∅∈∉⊆⊂∪∩∆ℕℤℝℂ∞Σ∑∏∫π

\begin{minted}{java}
// Java code
// ≠≤≥×·÷±∓√~≈≅⇔¬∧∨∀∃∅∈∉⊆⊂∪∩∆ℕℤℝℂ∞Σ∑∏∫π
\end{minted}

\end{document}